Physcomitrium is characterized by erect, symmetrical, and often urn-like capsules that lack peristomes. Infra-species variation of both the sporophyte and gametophyte of Physcomitrium pyriforme has led to many species being described over time in North America.

Physcomitrium commonly occurs on exposed soil often associated with spring-wet sites, often on alluvial mud and river banks, from near sea level to ca. 2500 m, and the capsules mature over winter into spring.